Behavioural interventions are grounded heavily in learning theory, they are built on the premise that most human behaviour is learned through the interaction between an individual and his or her environment. Behavioural interventions aim to teach and increase targeted positive behaviours and reduce or eliminate inappropriate or non-adaptive behaviours . Applied Behaviour Analysis (ABA) and Discrete Trial Training (DTT) continue to constitute the core features of most behavioural intervention programs.
There is universal agreement that behavioural interventions have produced positive outcomes for children with autism that are well supported by research. Few other treatment programs have been subjected to the level of research scrutiny that has been applied to behavioural interventions.
Applied behaviour analysis (ABA) is an intervention in which the principles of learning theory are applied in a systematic and measurable manner to increase, reduce, maintain, and/or generalize target behaviours. These behaviours include reading and other academic skills, social skills, communication, and adaptive living skills. Adaptive living skills include gross and fine motor skills, eating and food preparation, toileting, dressing, personal self-care, domestic skills, time and punctuality, money and value, home and community orientation, and work skills.
Discrete trial training involves breaking down specific skills into small discrete components or steps which are then taught in a graduated fashion. Only the child's correct responses are reinforced whereas incorrect or off-task behaviours are ignored. DTT and ABA are not synonymous; rather DTT represents one of several teaching strategies in the ABA tool box.
Nevertheless, the most frequently cited and recommended intensive behavioural programs (Lovaas, 1981; Maurice, Green, & Luce, 1996) continue to focus on DTT as the primary and predominant strategy for teaching children with autism.
Intensive Behavioural Intervention (IBI) or Early Intensive Behavioural Intervention (EIBI)
The generic terms intensive behavioural intervention (IBI) and early intensive behavioural intervention (EIBI) refer to behavioural interventions that are intensive and comprehensive. The intensity of a program relates to the number of hours of treatment the child receives per week as well as the intensity of training, curriculum, evaluation, planning, and coordination.
Severe behaviour disorders may be treated with intensive behavioural intervention. Proponents point out that children with autism typically do not learn from their environment spontaneously, and therefore need to be taught virtually everything they are expected to learn.
Intensive means one-to-one treatment in which carefully planned learning opportunities are provided and reinforced at a high rate by trained therapists and teachers for at least 30 (preferably 40) hours per week, 7 days a week, for at least two years. Because true generalization of therapy effects means that newly acquired behaviours need expression in a variety of settings, with a variety of people, behavioural interventions require the expansion of the role of therapy provider to include parents, teachers, siblings, and peers. The provision of consistent therapy during interactions with parents, siblings, and peers at home and at school is central to the creation of a complete therapeutic environment which supports generalisation.
There seems little contention that IBI programs produce positive outcomes for children with autism. Mesibov (1993) stated that it is not surprising that such intensive intervention should result in positive and lasting results, particularly as behavioural approaches have been used effectively with children with autism for many years.
Based on principles of ABA, the Lovaas program, developed by the University of California, Los Angeles, Young Autism Project under the direction of Ivaar Lovaas, uses time-intensive (40 hours per week) behavioural intervention techniques to treat children of two to three years of age, over a two to three year period. First stages of the program focus on teaching self-help and receptive language skills. The second stage of the intervention emphasizes the teaching of expressive language and interactive play with peers.
Lovaas (1987) conducted an evaluation of a behavioural treatment program for young children with autism, developed at the University of California, Los Angeles (UCLA). The participants were 38 children with autism under 4 years of age. The children were assigned to two groups: an experimental group of 19 children and a control group of 19 children. The experimental group received one-to-one behavioural treatment using methods of applied behaviour analysis for 40 hours per week over 2-3 years. Treatment occurred in the home and school setting. The control group received 10 or less hours of therapy a week over the same period of time. A second control group of 21 children with autism also received 10 or less hours of therapy per week through a nearby agency but no treatment input from the researchers.
A number of treatment outcomes were reported including:
Following the treatment:
For other treatment outcomes see full text at http://www.health.gov.au/internet/main/publishing.nsf/Content/mental-child-autrev-toc .
Smith et al. (2000) compared the outcomes of an intensive behavioural program with those of a parent training program for children with autism. The participants were 15 children with autism, 13 of whom had no functional speech. The children were randomly assigned to either the behavioural treatment or parent training group. Children in the behavioural group received an average of 25 hours per week over 12 months. The hours of treatment subsequently reduced over a period of 1-2 years. The parent training group received 3-9 months of parent training. At follow-up, the intensive treatment group scored significantly higher than the parent training group on measures of intelligence, visual-spatial skills, language, and academics. There were no significant differences for adaptive functioning or behaviour problems. Participants with less severe forms of autism (PDD-NOS) appeared to have gained more.
Sallows and Graupner (2005) compared the outcomes of an intensive clinic-directed behavioural intervention with those of a less intensive parent-directed behavioural intervention for 23 young children with autism. The children, aged between 24 and 42 months, were randomly assigned to the two groups. The intensive group comprised 13 children in order to replicate the parameters of the original study by Lovaas (1987). Both groups of children received treatment based on the UCLA model. The researchers intended the children in the clinic-directed group receive 40 hours of treatment per week. The parent-directed group received an average of 32 hours. A battery of tests was administered to each child prior to treatment in order to measure intelligence, communication skills, and adaptive behaviour. Assessments were repeated annually and at post-treatment. The Autism Diagnostic Interview-Revised was administered pre- and post-treatment. The results indicated that treatment outcomes across cognitive, language, adaptive behaviour, social, and academic measures were similar for both groups of children.
The outcomes of the study by Sallows and Graupner (2005) are broadly consistent with those of Lovaas (1987). Design strengths including diagnostic rigor associated with the use of the Autism Diagnostic Interview-Revised; random group assignment; and the use of procedures supported by research such as engaging the child, using powerful motivators, and augmentative and alternative communication strategies add weight to these findings. However, consideration must be given to the relatively small sample size, the lack of a control group not receiving the treatment (both groups in the study received IBI, either clinic based or parent directed), the potential bias associated with the involvement of the authors in administering assessments (lack of 'blind' assessors), and the fact that children with IQ scores below 35 were excluded from the study. The results suggest that early intensive behavioural intervention is an effective form of treatment for children with autism. The type of program (clinic-directed or parent-directed) did not appear to influence outcomes, nor did small variations in intensity of treatment between the two groups. The lack of a non-treatment control group or a comparison group receiving a different type of intervention means conclusions cannot be drawn in relation to outcomes compared to no treatment or different treatment programs.
Sallows and Grauper (2005) reported that parent managed programs were as effective as the clinic based program in their study and found little difference between a group of children who received a more intensive clinic-directed behavioural intervention and a group of children who received slightly less intensive parent-directed therapy.
(Approximately 40 hours for clinic-directed behavioural intervention as compared to 32 hours for the parent-directed group).